Method of lamp construction



Dec. 22, 1931. RS HM DT 1,837,886

METHOD OF LAMP cousmucnou Filed Ma 15, 1930 Patented Dec. 22, 1931 UNITED. STATES PATENT OFFICE JOHN F. SCHMIDT, OF CINCINNATI, OHIO, ASSIGNOR TO THE CORCOBAN-BROWN LAMP COMPANY, OF CINCINNATI, OHIO, A. CORPORATION OF OHIO Application filed May 15,

The method of lamp construction I am about to describe has for an object to produce from a single piece of sheet metal, a lamp body and closure which, through the operations I am about to describe, will insure accuracy of sizes,.ease of manufacture, reduction of costs, saving of material, and reductionin the number of manufacturing operations required to produce a lamp of the genoral type I have shown as exemplary of the invention I w1ll 110w disclose.

In the drawings, Fig. 1 is a sectional elevation of the first step in the drawing of a la mp bod Y and closure from a sin le iece of metal.

Fig. 2 is a view similar to Fig. 1, but show-' ing the second step which I take in preparing the body and closure for further manufacture.

Fig. 3 is a sectional elevation showing the third step which completes the formation of the body made in accordance with my invention.

Fig. 4 is a sectional elevation which shows the second step leadingto the completion of a lamp closure for the lamp body shown in Fig. 3 and from the same blank from which the body was produced.

Fig. 5 is a View similar to 4, but showing a closure which has been completed from the partially completed closure shown in Fig.

' 4 by a third step in the method I will describe,

readyfor cooperation with the body shown in Fig. 6. a v

Fig. 6 is a sectional elevation disclosing an assembly of the elements shown in Figs. 3 and 5.

Previous to the step shown in Fig.1, I cut a circular blank ofsheet metal, whichwill be of sufficient diameter to permit of the formamn'rnon or LAM]? CONSTRUCTION 1930. Serial No. 452,667.

sion shape 13 in the metal of the cup shape when rolled or otherwise depressed therein. I accomplish the formation of this depression simultaneously with the operation of cutting the portion 14- from the body portion 15, the former portion being used for the closure rim, as will be explained. This cutting operation along the line 12, causes the metal of the cup to be depressed into the groove of the block or form upon which the cup is located for this operation, and is accomplished purposely in this manner so that each of the pieces thus resulting will have an inturned edge as at 16 and 17 on the closure piece 14 and body piece 15 respectively. shaping operation the forward uneven edge 11 of the closure piece is removed by a trimming operation along the line 18, which also rgduce's the closure piece to the proper width preparatory to completing the closure. \Vith this second step completed, there are now two pieces completely shaped and trimmed to size ready for the separate handling and completion.

pletes the body, is shown in Fig. 3. This imultaneously with this cutting and The third step now taken, and which bm consists in merely rolling or otherwise shaping the-edge of the body piece so that it is provided with an intul'ned wall 19 and a forwardly extending flange 20.' The wall 19 forms a shoulder against which the closure is brought in assembling the lamp after completion, and the flange, which is preferably slightly tapered, receives and guides the closure into position on the body. In the forming of this wall and flange, the slightly inturned edge 17 performs the function of giving themetal of the body an easy start so that there is no chance of its splitting ortearing when forced into the shape shown in Fig. 3. Thus is the body completed, ready for such minor operations as making provisions for closure fastenings, connector mountings, lamp mountings, and the like.

I will now describe the operation of completing the closure. The first operation which consists in cutting off and trimming, and which has been described, also included the slight inturning of one edge of the elesure. This, asin the case of edge 17, was done so that the ring ofmetal is stifi'ened, whereby a second operation, which I will now describe, could be carried out without the 7. formation of the turned in edge 16. T

shown. The closure is now in condition for' i the closure will now be describe scribed.

metal of the edge splitting or tearing. This second operation consists in completing the is is accomplished by rolling, spinning, pressing oi otherwise forcing the partially turned edge 16 tobecome a reversed edge as at 21 in Fi 4. Thus is a stiff, truly circular and smoot finished edge produced on the rear edge of the closure.

The third and final forming o eration of This is illustrated in Fig. 5.- Here, it will be found, that the forward true edge 22, which was produced-by the cut 18, has been turned inwardly along a relatively wide roll formation 23 to produce a pleasing annular framing or rim around the closure glass with which the rim is supplied when the lamp is l y equipped. This roll is produced by rolling, pressing or otherwise causing the metal of the rim to be formed into the shape completion by providing it with the usualand suitable added feature by means of -which it mounts the closureglass, and, in turn, is mounted on the lamp body which is shown 'in Fig. 3 and .which has been de- Reference is now made to Fig. 6, in which the body and closure'are shown in cooperative relation, in order that the value of thus producing these two important elements of the .lamp from a singlepiece of metal, may be appreciated, by disclosing the correct and accurate sizing of these parts for each other, as well as the fact that they have in this manner been made without great waste'of material, such as is occasioned when the rimblank-is-cut from a separate disc of metal, thus necessitating the cutting out of a center disc of metal which has to bewasted for the most part even though smaller parts can be" 'made from it. One point to which I draw attention is the fact that I purposely produce a slight inturning on but one edge of the closure annulus, as shown at 16 in Fi 2, while the opposite edge 22, as shown in ig. 4, is straight. This difierence of initial formation is for specific purposes. In turning the rear edge 21, the shortness of the turn necessitates a preliminary starting. of the metal in order that no buckling, tearing or cracking would occur in forming such a short inward turn, whereas, in turning. such an edge as is shown in Fig. 5 at 23, the curvar ture in the die is of necessity so gradual that "abruptness, such as at 21, is not present,

hence enabling the metal to be rolled, pressed for the same purpose as that done on the closure, for the reason that the abruptness of the turns and shoulders adjacent to wall 19 of the body necessitates this preliminary starting operation.

Having thus described my invention, what I claim is:

A method oflamp construction consisting in forming from a sheet metal blank a cup of cylindrical wall shape, forming in the wall of the cup a circular depression at a' predetermined distance fromv the edge, cuttim through the depression at its greatest dept and thus leaving a partially turned edge on each of the severed portions, forming a shoulder on the partially turned edge of the remaining portion of the cup, formlng a re- I entrant flange on the partially turned edge of the ring-like severed portion, to fit the shoul der, and forming a flange on the remaining edge of the ring-like portion sure glass.

In testimony whereof I hereunto aflix my signature.

JOHN F. SCHMIDT.

or otherwise formed into the shape 23 as shown. This preliminary inturning of the edge of. the lamp body," as at 17 is also done to mount a c1o-- 

